Documentation/driver-api/early-userspace/buffer-format.rst includes the
specification for checksum-enabled cpio archives. Implement support for
this format in gen_init_cpio via a new '-c' parameter.
Suggested-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: David Disseldorp <ddiss@xxxxxxx>
---
usr/gen_init_cpio.c | 54 +++++++++++++++++++++++++++++++++++++--------
1 file changed, 45 insertions(+), 9 deletions(-)
diff --git a/usr/gen_init_cpio.c b/usr/gen_init_cpio.c
index 9a0f8c37273a..dc838e26a5b9 100644
--- a/usr/gen_init_cpio.c
+++ b/usr/gen_init_cpio.c
@@ -1,6 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
@@ -25,6 +27,7 @@
static unsigned int offset;
static unsigned int ino = 721;
static time_t default_mtime;
+static bool do_csum = false;
struct file_handler {
const char *type;
@@ -78,7 +81,7 @@ static void cpio_trailer(void)
sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
"%08X%08X%08X%08X%08X%08X%08X",
- "070701", /* magic */
+ do_csum ? "070702" : "070701", /* magic */
0, /* ino */
0, /* mode */
(long) 0, /* uid */
@@ -110,7 +113,7 @@ static int cpio_mkslink(const char *name, const char *target,
name++;
sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
"%08X%08X%08X%08X%08X%08X%08X",
- "070701", /* magic */
+ do_csum ? "070702" : "070701", /* magic */
ino++, /* ino */
S_IFLNK | mode, /* mode */
(long) uid, /* uid */
@@ -159,7 +162,7 @@ static int cpio_mkgeneric(const char *name, unsigned int mode,
name++;
sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
"%08X%08X%08X%08X%08X%08X%08X",
- "070701", /* magic */
+ do_csum ? "070702" : "070701", /* magic */
ino++, /* ino */
mode, /* mode */
(long) uid, /* uid */
@@ -253,7 +256,7 @@ static int cpio_mknod(const char *name, unsigned int mode,
name++;
sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
"%08X%08X%08X%08X%08X%08X%08X",
- "070701", /* magic */
+ do_csum ? "070702" : "070701", /* magic */
ino++, /* ino */
mode, /* mode */
(long) uid, /* uid */
@@ -293,6 +296,29 @@ static int cpio_mknod_line(const char *line)
return rc;
}
+static int cpio_mkfile_csum(int fd, unsigned long size, uint32_t *csum)
+{
+ while (size) {
+ unsigned char filebuf[65536];
+ ssize_t this_read;
+ size_t i, this_size = MIN(size, sizeof(filebuf));
+
+ this_read = read(fd, filebuf, this_size);
+ if (this_read <= 0 || this_read > this_size)
+ return -1;
+
+ for (i = 0; i < this_read; i++)
+ *csum += filebuf[i];
+
+ size -= this_read;
+ }
+ /* seek back to the start for data segment I/O */
+ if (lseek(fd, 0, SEEK_SET) < 0)
+ return -1;
+
+ return 0;
+}
+
static int cpio_mkfile(const char *name, const char *location,
unsigned int mode, uid_t uid, gid_t gid,
unsigned int nlinks)
@@ -305,6 +331,7 @@ static int cpio_mkfile(const char *name, const char *location,
int rc = -1;
int namesize;
unsigned int i;
+ uint32_t csum = 0;
mode |= S_IFREG;
@@ -332,6 +359,11 @@ static int cpio_mkfile(const char *name, const char *location,
goto error;
}
+ if (do_csum && cpio_mkfile_csum(file, buf.st_size, &csum) < 0) {
+ fprintf(stderr, "Failed to checksum file %s\n", location);
+ goto error;
+ }
+
size = 0;
for (i = 1; i <= nlinks; i++) {
/* data goes on last link */
@@ -343,7 +375,7 @@ static int cpio_mkfile(const char *name, const char *location,
namesize = strlen(name) + 1;
sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
"%08lX%08X%08X%08X%08X%08X%08X",
- "070701", /* magic */
+ do_csum ? "070702" : "070701", /* magic */
ino, /* ino */
mode, /* mode */
(long) uid, /* uid */
@@ -356,7 +388,7 @@ static int cpio_mkfile(const char *name, const char *location,
0, /* rmajor */
0, /* rminor */
namesize, /* namesize */
- 0); /* chksum */
+ size ? csum : 0); /* chksum */
push_hdr(s);
push_string(name);
push_pad();
@@ -464,7 +496,7 @@ static int cpio_mkfile_line(const char *line)
static void usage(const char *prog)
{
fprintf(stderr, "Usage:\n"
- "\t%s [-t <timestamp>] <cpio_list>\n"
+ "\t%s [-t <timestamp>] [-c] <cpio_list>\n"
"\n"
"<cpio_list> is a file containing newline separated entries that\n"
"describe the files to be included in the initramfs archive:\n"
@@ -499,7 +531,8 @@ static void usage(const char *prog)
"\n"
"<timestamp> is time in seconds since Epoch that will be used\n"
"as mtime for symlinks, special files and directories. The default\n"
- "is to use the current time for these entries.\n",
+ "is to use the current time for these entries.\n"
+ "-c: calculate and store 32-bit checksums for file data.\n",
prog);
}
@@ -541,7 +574,7 @@ int main (int argc, char *argv[])
default_mtime = time(NULL);
while (1) {
- int opt = getopt(argc, argv, "t:h");
+ int opt = getopt(argc, argv, "t:ch");
char *invalid;
if (opt == -1)
@@ -556,6 +589,9 @@ int main (int argc, char *argv[])
exit(1);
}
break;
+ case 'c':
+ do_csum = true;
+ break;
case 'h':
case '?':
usage(argv[0]);
--
2.31.1
